Lever connection to syncring

ABSTRACT

A mechanical joint for connecting each of the actuating levers on a row of variable position engine vanes to a common synchronizing ring including a flattened cylindrical slider fitting in a cylindrical recess in the actuating lever and having a stepped hole to receive a substantially radially extending pin in the synchronizing ring.

BACKGROUND OF THE INVENTION

In multiple stage axial flow compressors it has frequently beendesirable to adjust the position of all of the individual vanes in oneor more rows of stator vanes, thereby varying the flow area and/or angleof discharge to improve the performance of the associated compressorstage and thereby the performance of the compressor. It is desirablethat the connections between the individual vanes of the row and thesynchronizing ring by which the vanes are actuated be formed to minimizelooseness in order to achieve the desired precision of cooperativeaction between the turning motion of the ring on an axis concentric tothe compressor and the pivotal movement of the vane on a substantiallyradial axis. The mechanisms disclosed also provide area contact betweensliding surfaces rather than point or line contact, thus minimizingsurface stress and wear.

The invention herein described was made in the course of or under acontract or subcontract thereunder, with the Department of the Navy.

SUMMARY OF THE INVENTION

According to the present invention each vane carries a lever at one endand this lever is connected to the synchronizing ring through aflattened cylindrical slider fitting in a cylindrical slot in theactuating lever and having a substantially radial hole to receive a pincarried by the synchronizing ring. More specifically, the ring ischannel shaped to accept the end of the lever in the channel, and thehole in the slider engages the pin between its ends which are supportedby the synchronizing ring.

The foregoing and other objects, features, and advantages of the presentinvention will become more apparent in the light of the followingdetailed description of preferred embodiments thereof as illustrated inthe accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a fragmentary sectional view through a compressor case andvane structure.

FIG. 2 is a sectional view along line 2--2 of FIG. 1.

FIG. 3 is a developed view of the interconnection between the lever andthe ring.

FIG. 4 is an enlarged sectional view through the sliding block.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring first to FIG. 1, the stub shaft 10 projecting from the outerend of the vane 12 is pivoted in the compressor casing 14 and hasmounted on the outer end an actuating lever 16, being held thereon as bya nut 18. Such a construction is well known in the art as for examplethe Corsmeier Pat. No. 3,356,288.

The free end of the lever 16 has a slot 20, FIG. 2, therein, the sidewalls of which are parallel to the centerline of the lever. These sidewalls are arcuate and form together the opposite sides of a cylindricalrecess 22. Fitting in this recess is a block 24, the opposite sides 26of which are cylindrical and of a dimension to fit in and slide on theside walls of the cylindrical recess 22. This block is thus a flattenedcylindrical slider.

This block or slider 24 has a central opening 28 therethrough to receivea pin 30, FIG. 1, by which the lever is actuated. The central opening asshown in FIG. 4, has a central cylindrical portion 32 closely fittingthe pin 30 and tapered end portions 34 to permit a freedom of movementfor the pin at the ends of the hole. The block 24 is free to slideendwise within the cylindrical slot in the lever and to pivot on an axiscoincident with the axis of the slot.

As shown in FIG. 1, the pin 30 is carried in a ring 36 circumferentiallymovable on the casing 14, the pin extending substantially radiallythrough the ring. The actuating ring is U-shaped with the open end ofthe U facing toward the lever. The pin is carried by the opposite sidesof the U and the block 24 has its opposed surfaces flattened to fitwithin the ring but out of contact with the opposite sides of the ring.Similarly, the slotted end of the lever is substantially the samethickness as the block so that the end of the lever also fits readilywithin the actuating ring. As the ring is moved circumferentially on thecasing the pin 30 carries the block 24 with it, thus turning the lever16 and providing a corresponding turning movement of the vane. Thepresent structure is of particular value since it minimizes thelooseness necessary to accommodate the relative movements, therebyassuring a precise movement of the vane. It will be understood that theabove-described mechanism is only one of many duplicate mechanismsconnected to the actuating ring. Each of the many vanes forming the rowof vanes is similarly connected to the actuating ring and all must movefreely to permit the desired adjustment of the many vanes simultaneouslyto control the performance of the stage of the device of which this rowof vanes forms a part.

Although the invention has been shown and described with respect to apreferred embodiment thereof, it should be understood by those skilledin the art that other various changes and omissions in the form anddetail thereof may be made therein without departing from the spirit andthe scope of the invention.

Having thus described a typical embodiment of my invention, that which Iclaim as new and desire to secure by Letters Patent of the United Statesis:
 1. In an axial flow compressor having a casing, a row of vanescarried by said casing and positioned substantially radially therein,each vane of the row being turnable on its radial axis to change theangle of the vane, and a ring positioned on and extending around thecasing, said ring by circumferential movement actuating the vanes, incombination with actuating means for each of the vanes including:a leverattached to the vane and moving therewith, said lever having a slot inthe end remote from the vane, said slot having opposed cylindrical sidesurfaces, a block slidably fitting in said slot and having opposedcylindrical sides cooperating with the surfaces of the slot, thecylindrical axis of the slot surfaces and block surfaces being parallelto the longitudinal axis of the lever, said block having a central holetherethrough at right angles to the cylindrical axis, and a pin carriedby and positioned substantially radially of the ring on the casing andextending through the central hole of the block.
 2. An actuating meansfor use in an axial flow compressor as in claim 1 in which the centralhole in the block has a central portion corresponding in dimension tothe pin and outwardly tapered portions from opposite ends of the centralportion to the opposite surfaces of the block.
 3. An actuating means foruse in an axial compressor as in claim 1 in which the block has opposedflattened surfaces to fit within the actuating ring, the latter beingU-shaped to receive the block.
 4. An actuating means for use in an axialflow compressor as in claim 1 in which the slotted end of the lever isalso less thick than the U-shaped ring to be received therein.